System for maintaining acceptable environmental conditions in an indoor swimming pool enclosure

ABSTRACT

A buoyant sheet material and apparatus utilizing the material are disclosed for preventing evaporation of water in an indoor swimming pool when the pool is not in use. The sheet material is formed with a layer of buoyant foamed plastic material and a thinner layer of water-impervious plastic material and it is wound on a roll rotatably mounted adjacent one side of the pool. When the pool is not in use, the sheet material is drawn from the roll and placed on the surface of the water in the pool to prevent evaporation of the water and to thereby maintain a relatively low humidity in the pool enclosure.

United States Patent 1 Morita [111 3,748,664 [451 July 31,1973

1 1 SYSTEM FOR MAINTAINING ACCEPTABLE ENVIRONMENTAL CONDITIONS IN ANINDOOR SWIMMING POOL ENCLOSURE [75] Inventor: Akio Morita, Tokyo, Japan[73] Assignee: Sony Corporation, Tokyo, Japan [22] Filed: Dec. 13, 1971[211 App]. No.: 207,154

Primary Examiner-Henry K. Artis Attorney-Lewis H. Eslinger et al.

[57] ABSTRACT Abuoyant sheet material and apparatus utilizing thematerial are disclosed for preventing evaporation of water in an indoorswimming pool when the pool is not in use. The sheet material is formedwith a layer of buoyant foamed plastic material and a thinner layer ofwater-impervious plastic material and it is wound on a roll rotatablymounted adjacent one side of the pool. When the pool is not in use, thesheet material is drawn from the roll and placed on the surface of thewater in the pool to prevent evaporation of thewater and to therebymaintain a relatively low humidity in the pool enclosure.

6 Claims, 5 Drawing Figures The present invention relates to a devicefor preventing evaporation of water from a pool and in particular to asheet material which is adapted to prevent evaporation of water from anindoor pool and any increase of humidity within the surroundingenclosure.

It is presently becoming more common for large apartment complexes andeven individual home owners to have indoor swimming pools constructedfor use by the residents. One problem which frequently arises with suchpools is that the water within the pool evaporates and increases thehumidity within the surrounding enclosures to extremely high,uncomfortable, and often intolerable levels. A number of mechanicalsystems have previously been proposed for eliminating this problem suchas for example dehumidifiers and specialized air conditioning systemswhich are adapted to remove the excess moisture within the surroundingpool enclosure. However, such systems are relatively expensive,particularly for the individual home owner, and are subject to numerousmechanical breakdowns so that the problems which they seek to overcomestill arise periodically. In addition to their own expense, such systemsrequire additional space in the surrounding swimming pool enclosure, oralternatively, their own separate enclosure outside of the building.This additional enclosure itself is an additional expense, is oftenunattractive, and often occupies valuable space suitable for otherpurposes.

Accordingly, it is an object of the present invention to preventevaporation of water in a swimming pool.

Yet another object of the present invention is to maintain a relativelylow level of humidity within an indoor swimming pool enclosure.

Yet another object of the present invention is to prevent evaporation ofwater in an indoor swimming pool by an arrangement which is relativelysimple and inexpensive in construction and durable in use.

In accordance with an aspect of the present invention, evaporation ofwater in a swimming pool, or other body of water, is prevented byplacing a sheet of buoyant, water impervious material on the surface ofthe water when the pool is not in use. As is well known, evaporation ofwater occurs at the surface of a body of water which is in contact withthe atmosphere. Molecules of water escape from the surface because oftheir kinetic energy and enter the atmosphere through the vapor layer atthe surface of the water and thereby increases the moisture content andthus the relative humidity of the surrounding atmosphere. When thisoccurs in an enclosure, for example the enclosure or room surrounding anindoor swimming pool, the humidity of the pool surround increasessubstantially and makes the room uncomfortable. By placing the buoyantimpervious sheet material of the present invention on the surface of thewater when the pool is not in use, evaporation of the pool water isprevented and as a result, the moisture content of the air, (i.e. thehumidity) in the pool surround is not increased.

2 layer. The foamed layer provides the buoyancy for the sheet and thewater-impervious film material prevents water molecules from escapingfrom the surface of the water to the atmosphere. The sheet material isformed The material utilized to form the buoyant sheet of the I presentinvention comprises a layer of foamed buoyant 6 plastic material,preferably polyurethane, and a thinner layer of water-impervious plasticmaterial, such as for example film polyurethane, laminated to the foamedwith a slightly larger peripheral configuration than the swimming pooland is adapted to be wound on a roll for storage when the pool is not inuse. The roll is rotatably mounted adjacent the swimming pool so thatsheet material thereon is conveniently available for placement on thesurface of the water when the pool is not in use.

In the illustrative embodiment of the invention, the

.roll is mounted in an enclosed casing which is adapted to be enbeddedin the ground surrounding the pool so that it is out of view but stillavailable for use. Automatic driving means may be provided for drawingthe sheet material from the roll over the surface of the water andautomatic return means may also be provided for rewinding the sheetmaterial when the pool is to be used.

The above, and other objects, features and advantages of this inventionwill be apparent in the following detailed description of anillustrative embodiment thereof which is to be read in connection withthe accompanying drawings, wherein:

FIG. 1 is a perspective view of pool partially covered by a buoyantsheet material for preventing evaporation of water in the pool,according to an embodiment of the present invention;

FIG. 2 is a sectional view of the pool and roll arrangement taken alongline 2--2 of FIG. 1;

FIG. 3 is a plan view, partly in section, and with parts broken away,taken along line 3-3 of FIG. 2;

FIG. 4 is an enlarged sectional view of the sheet material utilized inan embodiment of the present invention; and

FIG. 5 is a partial sectional view, similar to FIG. 2, of anotherembodiment of the invention.

Referring to the drawings in detail, and initially to FIG. 1 thereof, itwill be seen that a roll 10 of sheet material adapted to preventevaporation of water in a pool, in accordance with an embodiment of thepresent invention, is positioned adjacent an indoor swimming pool 12,located within an enclosure or room 14. Roll 10 is contained within acasing 16 embedded in the pool surround 17 adjacent the end 18 of thepool. Casing 16, which may be formed of concrete, metal or the like, hasan access hatch 19 and defines a chamber 20 in which the roll 10 ismounted. The latter is rotatably supported by its central shaft 21 on apair of bearing blocks 22 to permit winding and rewinding of the sheetmaterial 24 on the roll.

Sheet material 24 is formed of a flexible plastic laminate materialwhich is buoyant and water impervious. This material is formed of alayer of foamed and inflated beads of polyethylene material, which areformed in a heat treating process into the layer 28. This layer providesbuoyancy to the sheet material 24 and permits the material to float uponthe surface of the water in the pool, as more fully describedhereinafter. Sheet 24 also includes an upper layer 30 of waterimperviousmaterial, preferably supplied as a film sheet of polyethylene, which islaminated to layer 28 by an adhesive or by a heat sealing process. Layer28 is preferably between L5 to 2.0 mm. thick and film layer 30 ispreferably 0.03 mm. thick. Thus, sheet 24 is a very thin member and maybe wound on central roll shaft 21 in a compact configuration so that aminimum amount an indoor swimming of room in the pool surround isrequired for the roll and casing 16.

In one embodiment of the invention the pool coping 32, surrounding pool12, is provided with a slot 34 in the end 18 of the pool. Casing 16includes a complementary slot 36 through which sheet 24, from roll 10,passes to the surface of the water in the pool. Slot 34 may be providedwith a break roller 38 or the like in order to guide sheet 24 throughthe slot and to prevent it from engaging any sharp or angulated edges ofthe coping.

When the pool is not in use, it is desirable to cover the entire watersurface in the pool to prevent escape of water molecules into thesurrounding atmosphere and thereby avoid resulting increased humidity.In accordance with the illustrative embodiment of the invention, this isaccomplished by providing the free edge 40 of sheet 24 with a cross bar42 which is connected by a pair of pull ropes 44 to the sheaves 46. Thelatter are rigidly mounted on a winding shaft 48, which is adapted to berotated by a drive motor 50, to wind ropes 44 onto the sheaves andthereby draw sheet 24 over the surface of the water. Motor 50, shaft 48and sheaves 44 are contained within a second enclosure 52 embedded inthe pool surround l7 adjacentthe end 54 of thepool, i.e., the end of thepool opposite end 18.

Casing 52 includes a slot 56 therein through which ropes 44 and the end40 of sheet 24 pass when the sheet is extended. When the end 40 of sheet24 is moved to a position adjacent shaft 48, the sheet fully covers theentire water surface area of the pool with sheet 24 lying over the edges58 of the gutter 60 formed along the sides of the pool. The gutter is aconventional feature in most swimming pools which limits the depth ofthe water therein and which drains foreign material floating on the topof the water from the pool. Where such gutters are not provided, theropes 44 may of course extend closely along the sides of the pool or inslots formed along the sides. In the event that the surface 62 of thewater is below the level of coping edge 58, sheet 24, which is drawnloosely across the pool by motor 50 so that some slackness is permitted,will drop down and rest upon the surface of the water (FIG. 2).

Sheet 24 is formed in a configuration which is complementary to theconfiguration of the pool so that the entire water surface area of thepool will be covered by the sheet when in use. When the pool has anirregular shape, sheet 24 will have the same shape so that when it isfully extended it is completely complementary to the pool.Alternatively, a plurality of rolls may be utilized and they may bepositioned, as would be clear to one skilled in the art, so as to coverthe entire surface area of the irregularly shaped pool when they areextended. In any case, sheet 24 floats on the surface of the water andprovides a barrier for the escape of moisture from the surface of thepool. As a result, water vapor from the surface of the pool cannotescape to the atmosphere and increase the humidity within enclosure 14thereby is avoided.

It is noted, that while the present invention is described inconjunction with an indoor swimming pool, it is contemplated that theinvention can be utilized with outdoor swimming pools or other bodies ofwater where it is desired to prevent evaporation or the accumulation ofdirt and foreign material on the surface of the water.

When the pool is to be used, sheet 24 simply is rewound on roll 10. Forthis purpose a motor 64 is provided within enclosure 16 for rotatingroll in a direction to rewind sheet 24 thereon. Motor 60 is providedwith a conventional one-way clutch (not shown) so that it is not turned,and does not prevent unwinding of the sheet material, when sheet 24 iswithdrawn from roll 10 by motors 50. In addition, in order to dry thesheet 24 as it is rewound, enclosure 16 may be provided with anelongated bore 66 having an upper flared discharge opening 68 adjacentthe lower surface 70 of sheet 24 as it is rewound on roll 10. A supplyof warm air, drying talc or the like, may, in one embodiment, besupplied from a source thereof through a supply hose 72 for dischargethrough bore 66 and application to the lower surface of the sheet as itis being rewound. In this manner, excess moisture on the lower surfaceof the sheet is evaporated by the warm air, or absorbed by the talc, soas to avoid formation of mildew on the sheet during storage. Uponcompletion of the rewinding operation, bar 42 is adjacent slot 34 sothat it is completely out of view and away from the water surfacewhereby it does not interfere with the use of the pool and does notaffect the appearance thereof.

In another embodiment of the invention, enclosure 16 may be providedwith a slot 72 on its upper surface adjacent hatch 19, so'that sheet 24passes through the opening 72' over the top edge 74 of the coping andthence onto the surface of the water in the pool. Bythis arrangement,the possibility of water entering the chamber 20 of enclosure 16 issubstantially decreased.

In yet another embodiment of the present invention, which is useful withpools that have been previously constructed, roll 10 may be rotatablymounted on deck 17 surrounding the pool so that sheet 24 may bemanuallywithdrawn from the roll. This may be done, for example, by twopersons standing on either side of the roll, grasping the ends of pole42, and drawing the sheet over the surface of the pool as they walkalong its sides. In this embodiment, the roll may be provided with ahand crank to rewind the sheet material on the roll when the pool is tobe used. This arrangement is the simplest and most inexpensive systemfor preventing evaporation of moisture from the pool and in addition isrelatively simple to operate.

The present invention cooperates with the air conditioning systemutilized for the pool surround or enclosure since it preventsevaporation of the pool water and thus assists in maintaining arelatively low humidity within the pool surround. Accordingly, the sizeof the air conditioning system need not be as large as heretoforerequired, and with less moisture in the air that must be removed, thesystem can operate more efficiently. In addition, the water within thepool remains at a warmer temperature so that no water heater or at leasta much smaller water. heater than normal is required. It is well knownthat upon evaporation of water, the temperature of the water decreasesbecause the energy consumed in expelling the molecules of water from thesurface of the body of water reduces the total energy in the body ofwater and thus causes a decrease in its temperature. By preventingevaporation, the water within the pool does not lose this energy andthus is maintained at a relatively constant temperature.

Accordingly, it is seen that a relatively simple and inexpensive deviceis provided for maintaining a relatively low level of humidity within anenclosure for an indoor pool. The construction of the sheet material isadvantageous in that a relatively thin and light buoyant material isprovided to accomplish the purpose of the invention and as a result, theentire system is relatively compact and hidden from view so that theappearance of the pool surround is not encumbered and no operatingequipment is exposed in an area adjacent the pool where a swimmer orother person using the pool could possibly trip over it. In addition,the sheet material has a high buoyancy factor since a substantialportion thereof is formed of foamed polyethylene material which ishighly buoyant. Accordingly, there is little possibility for the sheetmaterial to sink under the surface of the water even when anaccumulation of moisture or objects from the pool surround fall upon itssurface.

Although illustrative embodiments of the present invention have beendescribed herein with reference to the accompanying drawings, it is tobe understood that the invention is not limited to those preciseembodiments, and that various changes and modifications may be effectedtherein by one skilled in the art without departing from the scope orspirit of this invention.

What is claimed is: i

l. A device for preventing evaporation of water in a pool when the poolis not in use comprising, a roll of buoyant water impervious sheetmaterial adapted to be rotatably mounted adjacent the pool, said sheetmaterial having the 'same general peripheral configuration of the poolwith which it is to be used and being formed of a layer of buoyantfoamed plastic material and a thinner layer of water impervious plasticmaterial, whereby said material is adapted to be unrolled and placed onthe surface of the water in the pool to prevent evaporation of the waterwhen the pool is not in use.

2. The device as defined in claim 1 wherein said foamed plastic layer isformed of a foamed polyethylene and said impervious layer is formed of afilm of polyethylene.

3. The device as defined in claim 2 including means for drawing saidsheet material from the roll thereof over the surface of water in thepool.

4. The device as defined in claim 3 including means for rewinding saidsheet material onto said roll prior to use of said pool.

5. The device as defined in claim 4 including an ena closure for saidroll adapted to be embedded in the ground surrounding the pool and meansrotatably mounting said roll in said, enclosure, said enclosure havingan opening therein through which said sheet material may be wound andunwound on the roll.

6. The device as defined in claim 2 wherein said foam layer is between1.5 and 2.0mm. thick and said film layer is approximately 0.03mm. thick.

1. A device for preventing evaporation of water in a pool when the poolis not in use comprising, a roll of buoyant water impervious sheetmaterial adapted to be rotatably mounted adjacent the pool, said sheetmaterial having the same general peripheral configuration of the poolwith which it is to be used and being formed of a layer of buoyantfoamed plastic material and a thinner layer of water impervious plasticmaterial, whereby said material is adapted to be unrolled and placed onthe surface of the water in the pool to prevent evaporation of the waterwhen the pool is not in use.
 2. The device as defined in claim 1 whereinsaid foamed plastic layer is formed of a foamed polyethylene and saidimpervious layer is formed of a film of polyethylene.
 3. The device asdefined in claim 2 including means for drawing said sheet material fromthe roll thereof over the surface of water in the pool.
 4. The device asdefined in claim 3 including means for rewinding said sheet materialonto said roll prior to use of said pool.
 5. The device as defined inclaim 4 including an enclosure for said roll adapted to be embedded inthe ground surrounding the pool and means rotatably mounting said rollin said enclosure, said enclosure having an opening therein throughwhich said sheet material may be wound and unwound on the roll.
 6. Thedevice as defined in claim 2 wherein said foam layer is between 1.5 and2.0mm. thick and said film layer is approximately 0.03mm. thick.